The field of the present invention is fuel injection systems, and more particularly, devices for mounting injector nozzles for such fuel injection systems.
Fuel injection systems generally employ nozzles which are fixed relative to the engine at either the intake manifold or the cylinder head to direct fuel received from a fuel distribution line toward the intake of the engine cylinders at appropriately timed intervals. Such nozzles are usually comprised of a solenoid valve arranged to inject in an intermittent manner the fuel supplied thereto through the fuel distribution line. The nozzle is directed to provide fuel toward the combustion chamber in the engine cylinder, often indirectly via the intake manifold.
Mounting devices for mounting injector nozzles on engines have previously been employed which include a pipe joint such as a nipple for joining the injection nozzle to the fuel distribution line and a means for directly affixing the nozzle to an engine element such as the cylinder head or the intake manifold. Such mounting devices often require close machining tolerances and close mounting tolerances in order to maintain an appropriate seal at the joints between the injection nozzles and the fuel distribution line and also between the injection nozzles and the engine.
The requirement for close tolerances and effective seals is often the result of the difficult environment in which the injection nozzle is located. The nozzle itself vibrates during the injecting operation. This vibration is transmitted to the joints with the engine and with the fuel distribution line causing undesirable loosening of the joints. Fuel is thus able to leak between components. Furthermore, with standard mounting systems, the injection nozzle as well as the fuel distribution line can easily become overheated from the engine. This is particularly true in a counterflow type engine in which the intake manifold is arranged above the exhaust manifold where heat convection adds to the adverse thermal environment. As a result, the fuel may partially vaporize to create adverse operating conditions.